Support for OpenAPI3

[souenzzo]

• Schema -> OpenAPI3
• Malli -> OpenAPI3 (using json-schema)
• Spec -> OpenAPI3
• Coercion for all content-types
• Coercion per content-type

Fixes #84

[souenzzo]

Malli is the only one that supports multiple content types

The API:

• Add :content-types ["application/json" "application/foo+json"] to your path/route/router.
• A key :content-type will be present in the option map, in your transformer.

I'm not sure if this API is enough.

I would like to have a feedback on it.

If this API seems to be enough, I can extend it to schema/spec too.

[piotr-yuxuan]

I praise this very good work, and am thankul that you did it! I wanted it so much but shamefully didn't work on it. I haven't tried this to run this diff but it looks quite great. I command your code quality and the extensive work you did 🚀 I quite like that Open API 3.0 and Swagger may coexist alongside.

I'm just a rando an GitHub and have no power on this repo, but I left a couple of minor comments that I believe might help smooth the approval process. Take them very freely. Please don't take the style comments very seriously: I didn't pedantically left them, they are more to help me understand and reflect on how to structure code 🙂

[piotr-yuxuan]

It is a very minor suggestion for this snippet and below. Feel free to discard.

Suggested change

	{:requestBody {:content (into {}
	(map (fn [content-type]
	(let [schema (->schema-object body {:in :requestBody
	:type :schema
	:content-type content-type})]
	[content-type {:schema schema}])))
	content-types)}})
	(->> content-types
	(map (juxt identity
	(comp #(do {:schema %})
	(partial ->schema-object body)
	#(do {:in :requestBody
	:type :schema
	:content-type %}))))
	(assoc-in {} [:requestBody :content]))

[piotr-yuxuan]

I do accept that this is most desirable (in some personal projects I exclude malli from reitit and import the latest version), but is it required by this diff? Would it be more appropriate in a dependency-related PR?

[piotr-yuxuan]

How does this vertical space compare with neighbouring ones?

[piotr-yuxuan]

I really like this thorough, nice docstring. I noticed top-level directories /examples and /doc, do you think it would be worth adding an example and some explanations there? might be just for the sake of completion, hinting at possible current limitations, and showing copy-paste-ready code.

[piotr-yuxuan]

?

Completely worth keeping if it's a helpful breadcrumb for later developer, I can't judge.

[StankovicMarko]

any plans on this getting merged?

[stathissideris]

Is there any work left on this? I'd be willing to help out.

[ikitommi]

Thanks for all the work on this! As this is a big change, planning to make a maintenance release before digging into this.

[ikitommi]

Merged with master as thought it was ok but there is a change in malli json schema rendering causing the tests fail now. we can fix those when review, sorry.

[coyotesqrl]

This is exciting. I've already had to hack in swagger->openapi on one project and never want to do that again, so being able to autogenerate openapi as easily as swagger would be great.

One thing I noticed on a very brief scan was that there didn't seem to be an analog to reitit.swagger-ui/create-swagger-ui-handler. Is that something likely to be added sometime shortly after this is released (hopefully that's soon), or am I seriously underestimating the effort required for that?

[opqdonut]

I'm looking at what's needed to be able to merge this. It's a good base. The most notable missing piece is the validation/coercion for the per-content-type models.

[opqdonut]

My work is in #588. It contains the stuff in this PR.